Detoxification and repair process of ozone injury: from O3 uptake to gene expression adjustment.
Plants react to O(3) threat by setting up a variety of defensive strategies involving the co-ordinated modulation of stress perception, signalling and metabolic responses. Although stomata largely controls O(3) uptake, differences in O(3) tolerance cannot always be ascribed to changes in stomatal conductance but cell protective and repair processes should be taken into account. O(3)-driven ROS production in the apoplast induces a secondary, active, self-propagating generation of ROS, whose levels must be finely tuned, by many enzymatic and non-enzymatic antioxidant systems, to induce gene activation without determining uncontrolled cell death. Additional signalling molecules, as ethylene, jasmonic and salicylic acid are also crucial to determine the spreading and the containment of leaf lesions. The main recent results obtained on O(3) sensing, signal transduction, ROS formation and detoxification mechanisms are here discussed.
Castagna
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Department of Agricultural Chemistry and Biotechnology, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy. castagna@agr.unipi.it
Ranieri
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D000393:Air Pollutants / Q000378:metabolism / Q000633:toxicity*; D000975:Antioxidants / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D008658:Inactivation, Metabolic; D018384:Oxidative Stress; D010126:Ozone / Q000378:metabolism / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects* / Q000378:metabolism; D054046:Plant Stomata; D017382:Reactive Oxygen Species / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
D000393:Air Pollutants; D000975:Antioxidants; D005030:Ethylenes; D017382:Reactive Oxygen Species; D010126:Ozone; C036216:ethylene; D020156:Salicylic Acid